It is known of to make playing fields in synthetic grass by first constituting a substrate in clay (or even in cement), on which the covering of synthetic grass, usually in rolls, is placed. Sometimes a waterproof film is positioned between the substrate and the covering of synthetic grass for drainage of rainwater.
Despite synthetic grass being soft, the playing field transmits a hard sensation to the user however, especially when running, falling or chasing after a bouncing ball.
In fact, the synthetic grass covering is fully compressed under the user's weight, inasmuch as extremely yielding; so that the user immediately feels the presence of the compact substrate in clay.
Some solutions envisage the use of an under layer in soft synthetic material, for example rubbery material, positioned between the substrate and synthetic grass covering.
Such solution, however, poses serious problems for proper drainage of the playing field, in that the water tends to accumulate between the covering and rubbery under layer, creating puddles which take an extremely long time to dry.